Making nested aggregations to compare student result into materials through multiple months

[M-Samy]

@nahid
################ Json Data 1 ######################
{
"student_results": [
{
"month": "month1",
"results": [
{
"material_code": "Math",
"result": "20",
},
{
"material_code": "English",
"result": "50",
},
]
}
]
}

################ Json Data 2 ######################
{
"student_results": [
{
"month": "month2",
"results": [
{
"material_code": "Math",
"result": "30",
},
{
"material_code": "English",
"result": "48",
},
]
}
]
}

################ Expected result ######################

{
"student_results": [
{
"month": "month2",
"results": [
{
"material_code": "Math",
"result": "30",
},
{
"material_code": "English",
"result": "50",
},
]
}
]
}